package interfaces.tests;

public interface CountPowerfulNumbers {
	/*
	 * A powerful number is a positive integer m that for every prime number
	 * p dividing m, p*p also divides m.
	 * 
	 * (a prime number (or a prime) is a natural number that has exactly two
	 * (distinct) natural number divisors, which are 1 and the prime number
	 * itself, the first prime numbers are: 2, 3, 5, 7, 11, 13, ...)
	 * 
	 * The first powerful numbers are: 1, 4, 8, 9, 16, 25, 27, 32, 36, ...
	 * 
	 * Please implement this method to return the count of powerful numbers
	 * in the range [from..to] inclusively.
	 */
	public int countPowerfulNumbers(int from, int to);
}
